Capsular intraocular lens implant having a refractive liquid therein

ABSTRACT

An intraocular lens having a light-transmitting optic ( 32, 94   a,    94   b,    142, 216 ) comprised of a synthetic light-refractive material ( 40, 102 ) operably coupled with a flexible optic positioning member ( 34, 62, 74, 84, 100, 210 ) to refract light onto the retina in order to correct refractive errors in the eye ( 10 ). The refractive material has an index of refraction of from about 1.36 to 1.5 or higher. The optic positioning member ( 34, 62, 74, 84, 100, 210 ) is constructed of a flexible synthetic resin material such as polymethylmethacrylate and permits focusing upon objects located near to and far from the viewer. The optic ( 32, 94   a,    94   b,    142, 216 ) of the present invention possess greater refractive capability than optics conventionally used in IOL construction, and permits retinal receipt of the image being viewed in order to correct refractive errors.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an accommodating intraocular lens implant (IOL), containing a refractive material therein, for surgical replacement of the natural crystalline lens to treat refractive errors in the human eye.

[0003] 2. Description of the Prior Art

[0004] Refractive errors in the eye affect one's ability to properly focus an image upon the retina due to a change in the refractive medium of the eye, e.g., the cornea, the natural crystalline lens, or both. The refractive errors pertinent to this application include myopia, hyperopia, and presbyopia. A myopic lacks the ability to focus an image located at a distance from the viewer because the cornea has become elongated, thereby increasing the eye's focal length. A hyperopic lacks the ability to focus on objects located near the viewer because the cornea is not elongated enough or is too flat, and cannot refract light properly upon the retina. Instead, light entering the eye does not bend sharply enough to focus upon the retina. In contrast to myopia wherein the image is brought to focus in front of the retina, hyperopia causes the image to focus behind the retina. Presbyopia is another type of refractive error which results in the inability of the eye to focus because of hardening of the natural crystalline lens. The hardened natural crystalline lens prevents focusing upon objects located near to the viewer. Presbyopia occurs in conjunction with myopia or hyperopia.

[0005] The known treatment varies with the type of refractive error to be corrected. Each of the refractive errors may be corrected by external spectacle lenses. Also, refractive surgery is known in the art for correcting the aforementioned refractive errors, and includes radial keratotomy, astigmatic keratotomy, photoreflective keratectomy, and laser in situ keratomileusis (LASIK). Each of the refractive surgical methods mentioned above involve making multiple incisions into the cornea in order to reshape it. Possible side effects of refractive surgery include irregular astigmatism, infection, or haze formation which could result in permanent changes in the cornea and possible loss of best-corrected visual acuity. A possibility of under or over correction also exists with the aforementioned refractive surgeries. Furthermore, none of these refractive surgeries can be used to correct all of the above-referenced refractive errors.

[0006] Various IOLs have been used to treat cataracts. The first implant of an IOL within the eye to treat cataracts occurred in 1949. This experimental surgery attempted to place the replacement lens in the posterior chamber of the eye behind the iris. Problems such as dislocation after implantation forced abandonment of this approach, and for some period thereafter IOLs were implanted in the anterior chamber of the eye.

[0007] Others returned to the practice of inserting the IOL in the area of the eye posterior to the iris, known as the posterior chamber. This is the area where the patient's natural crystalline lens is located. When the IOL is located in this natural location, substantially normal vision may be restored to the patient, and the problems of forward displacement of the vitreous humor and retinal detachment encountered in anterior chamber IOLs are less likely to occur. IOLs implanted in the posterior chamber are disclosed in U.S. Pat. Nos. 3,718,870, 3,866,249, 3,913,148, 3,925,825, 4,014,049, 4,041,552, 4,053,953, and 4,285,072. None of these IOLs have accommodation capability.

[0008] IOLs capable of focusing offered the wearer the closest possible substitute to the natural crystalline lens. U.S. Pat. No. 4,254,509 to Tennant discloses an IOL which moves in an anterior direction upon contraction of the ciliary body and which is located anterior to the iris. Although the Tennant IOL claims to possess accommodation capabilities, it presents the same disadvantages as other anterior chamber lenses. U.S. Pat. No. 4,253,199 to Banko approaches the problem of providing a focusable IOL in a different manner, by providing a replacement IOL of deformable material sutured to the ciliary body. This IOL functions in much the same manner as the natural crystalline lens, but may cause bleeding because it requires sutures.

[0009] U.S. Pat. No. 4,409,691 to Levy claims to provide an accommodating IOL positioned within the capsule. This IOL is located in the posterior area of the capsule and is biased toward the fovea or rear of the eye. The Levy IOL is deficient because it requires the ciliary muscle to exert force through the zonules on the capsule in order to compress the haptics inward and drive the optic forward for near vision. However, the ciliary muscles do not exert any force during contraction because the zonules, being flexible filaments, exert only tension, not compression on the capsule. The natural elasticity of the IOL causes the capsule to become more spherical upon contraction of the ciliary muscle. Thus, there is no inward force exerted on the capsule to compress the haptics of the Levy IOL, and therefore accommodate for near vision. Even if such force were somehow available, the Levy IOL's haptics are loaded inward when accommodating for near vision. Since accommodation for near vision is the normal status of the capsule, the Levy IOL's haptics are loaded, reducing the fatigue life of the springlike haptics.

[0010] U.S. Pat. No. 5,674,282 to Cumming is directed towards an allegedly accommodating IOL for implanting within the capsule of an eye. The Cumming IOL comprises a central optic and two plate haptics which extend radially outward from diametrically opposite sides of the optic and are movable anteriorly and posteriorly relative to the optic. However, the Cumming IOL suffers from the same shortcomings as the Levy IOL in that the haptics are biased anteriorly by pressure from the ciliary bodies. This will eventually lead to pressure necrosis of the ciliary body.

[0011] Finally, U.S. Pat. No. 4,842,601 to Smith discloses an allegedly accommodating IOL having anterior and posterior members which urge against the anterior and posterior walls of the capsule. The muscular action exerted on the capsule will cause the IOL to flatten, thereby changing the focus thereof. The Smith IOL is formed of first and second plastic lens members connected to one another adjacent their peripheral edges so as to provide a cavity therebetween. The connection between the lens members is accomplished by way of a U-shaped flange on the first member which forms an inwardly facing groove for receiving an outwardly extended flange on the second member. The Smith IOL is faulty because the structure of the lens members makes surgical implantation thereof extremely difficult to accomplish, even for highly skilled surgeons. Furthermore, the Smith IOL requires sutures which increases the risk of bleeding.

[0012] The IOLs discussed above replaced the opaque crystalline lens symptomatic of cataracts through a small incision in the iris and anterior wall of the biological capsule. The IOLs for the treatment of cataracts differed from the present invention in that the present invention utilizes a highly refractive material to compensate for defects in the eye's natural refractive media, e.g, the cornea and the natural crystalline lens.

[0013] There is a great need in the art for a lightweight IOL which can be used to correct a variety of refractive errors in conjunction with other eye defects which require replacement of the natural crystalline lens, such as cataracts. This IOL should be readily insertable into the capsule and should last for a substantial number of years without damaging any of the eye components.

SUMMARY OF THE INVENTION

[0014] The IOL of the present invention addresses this need because it provides a lightweight accommodating IOL, containing a highly refractive material therein, which is safe for long term use in an eye. The present invention presents a significant advance in the art because it provides an IOL for the safe and effective treatment of refractive errors in combination with other defects such as cataracts.

[0015] In more detail, the IOL comprises a resilient optic formed of a highly refractive material operably coupled to a flexible optic positioning member to change shape in response to ciliary body movement, i.e., contraction and retraction of the ciliary body. When the ciliary body relaxes or retracts, it causes the zonules to elongate and exert a tensional pull upon the IOL. Thus, the IOL becomes discoid in shape and allows the viewer to focus upon objects located at a distant therefrom. Similarly, when the ciliary body contracts, it becomes thicker and causes the zonules to ease the tensional pull. Thus, the IOL becomes spheroid in shape and allows the viewer to focus upon objects located near to the viewer. As noted above, the optic is formed of refractive material that has an index of refraction of from about 1.36 to 1.5 or higher (e.g., hydrocarbon oil, silicone oil, or silicone gel). In one type of IOL in accordance with the invention, use is made of a pre-formed capsule having a thin, continuous wall wherein the refractive material is enveloped.

[0016] The optic may be coupled with various optic positioning members commonly used in IOL construction depending upon the user's eyesight. The optic may be positioned within the capsule of the eye such that the anterior surface of the optic faces either the anterior or the posterior portion of the eye. When the optic is positioned to face the posterior portion of the eye, the optic will vault posteriorly in response to contraction of the ciliary body. However, the change in the radius of curvature of the optic will counteract the effects of the negative accommodation, i.e., movement of the optic posteriorly. The resiliency of the optic permits a small change in radius of curvature which, when coupled with the relatively high index of refraction of the refractive material, results in an optic having greater light-bending properties than conventional optics.

[0017] Another preferred embodiment presents a resilient optic and a posterior rigid optic both operably coupled on opposed sides of an optic positioning member to change shape in response to ciliary body movement. The optics are positioned on opposite segments of the optic positioning members such that they share the same focal point. A similar embodiment transposes the structure described immediately above by implanting the IOL within the eye such that the rigid optic is the anterior optic and the resilient optic is the posterior optic.

[0018] Another embodiment of the present invention presents two optics positioned on the same segment of the optic positioning member wherein a rigid optic surrounds a resilient optic. Another embodiment similar to the embodiment discussed immediately above, presents two optics positioned on the same segment of the optic positioning member wherein a resilient optic surrounds a rigid optic. In this embodiment, the resilient optic changes shape in response to ciliary body movement while the rigid optic essentially retains its shape.

[0019] Yet another preferred embodiment of the IOL of the present invention includes an optic positioning member comprised of an enclosed flexible bag having resilient fill material therein. The enclosed flexible bag presents an anterior segment and an opposed posterior segment, each having an optic. The optic positioning member is pre-formed to present opposed optic surfaces, hence, the optics are integral with the optic positioning member. The resilient fill material is comprised of the same refractive material used in the above-referenced resilient optic construction. This embodiment also functions similarly to the IOLs discussed above because the anterior optic surface moves anteriorly and the posterior optic surface moves posteriorly in response to contraction of the ciliary body. The optic surfaces of the flexible bag optic positioning member present a small change in the radius of curvature (e.g., 5-4.6 mm) from the accommodated to disaccommodated shapes, coupled with high refractive power thereby permitting retinal receipt of an observed image.

[0020] Another embodiment of the present invention is similar to the embodiments having opposed optics, described above, except that the optic positioning member of this embodiment does not completely house the refractive material. The refractive material of this IOL protrudes outward to extend beyond the outer margins of the anterior segment through an opening in the optic positioning member to define a resilient optic. The posterior segment of the optic positioning member supports a second posterior rigid optic positioned in opposition to the resilient optic. The rigid optic is constructed of the same material as the optic positioning member. The resilient material is captively retained by the segments of the optic positioning member, but also directly contacts the biological capsule. Contraction of the ciliary body transfers sufficient force to the resilient and protuberant refractive material which in turn defines an optic operable to change shape in response to ciliary body movement. This embodiment may be constructed without the addition of a second opposed rigid optic depending upon identifiable surgical needs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a vertical sectional view showing an IOL of the invention within the capsule of an eye, with the eye focused on an object distant from the viewer;

[0022]FIG. 2 is a vertical sectional view of a preferred IOL of the invention;

[0023]FIG. 3 is an anterior perspective view of the IOL of FIGS. 1 and 2;

[0024]FIG. 4 illustrates another embodiment of the invention;

[0025]FIG. 5 illustrates another embodiment of the invention;

[0026]FIG. 6 illustrates another embodiment of the invention;

[0027]FIG. 7 is a vertical sectional view of the IOL of FIG. 3 showing the optic bonded to the anterior surface of the anterior segment of the IOL of the present invention;

[0028]FIG. 8 is a vertical sectional view of the IOL of FIG. 3 showing the optic bonded to the posterior surface of the anterior segment of the IOL of the invention;

[0029]FIG. 9 is a vertical sectional view of another embodiment of the invention showing the optic located at the anterior segment of the IOL and a posterior rigid optic at the posterior segment of the IOL;

[0030]FIG. 10 is a vertical sectional view of the IOL of FIG. 9 positioned within the eye, with the optic located at the posterior segment of the IOL and a rigid optic at the anterior segment;

[0031]FIG. 11 is a vertical sectional view of a preferred IOL of the invention within the capsule of an eye, with the eye focused on an object distant from the viewer;

[0032]FIG. 12 is a view similar to that of FIG. 11, but illustrating the IOL in an accommodated position owing to contraction of the ciliary body;

[0033]FIG. 13 is a plan view of a preferred IOL of the invention;

[0034]FIG. 14 is a vertical sectional view taken along line 14-14 of FIG. 13; and

[0035]FIG. 15 is a greatly enlarged fragmentary of the IOL of FIGS. 11-14;

[0036]FIG. 16 is a vertical sectional view similar to that of FIGS. 7-10, but illustrating the optic constructed without an enveloping capsule;

[0037]FIG. 17 is a vertical sectional view of another embodiment of the present invention, illustrating a resilient optic surrounded by a rigid optic;

[0038]FIG. 18 is a vertical sectional view of another embodiment of the present invention, showing an IOL of the invention within the capsule of an eye, with the eye focused on an object located at a distance from the viewer; and

[0039]FIG. 19 is a view similar to that of FIG. 18, but illustrating the IOL in an accommodated position owing to contraction of the ciliary muscle;

[0040]FIG. 20 is a vertical sectional view showing an IOL of the invention within the capsule of an eye, with the optic positioned posteriorly;

[0041]FIG. 21 is a view similar to that of FIG. 20, but illustrating the IOL in a disaccommodated position owing to retraction of the ciliary muscle; and

[0042]FIG. 22 is a vertical sectional view of another embodiment of the IOL of the present invention positioned within the capsule of the eye.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Referring now to the drawings, the present invention is in the form of an IOL for surgical replacement of the natural crystalline lens in the treatment of refractive error in the human eye. FIG. 1 shows the various components of the human eye 10 pertinent to this invention. Briefly, the eye 10 includes an anterior portion 12 and a posterior portion 14. The anterior portion 12 of the eye 10 is covered by a cornea 16 which encloses and forms an anterior chamber 18. The anterior chamber 18 contains aqueous fluid and is bounded at the rear by an iris 20. The iris 20 opens and closes to admit appropriate quantities of light into the inner portions of the eye 10. The eye 10 also includes a capsule 22 which ordinarily contains the natural crystalline lens (which would be located at numeral 24 in the natural, unmodified eye). The eye 10 includes a ciliary muscle or body 26 having zonular fibers 28 (also referred to as zonules) which are attached to the eye 10. The vitreous humor 30 is located posterior to the capsule 22 and anterior to the retina (not pictured). The vitreous humor 30 contains vitreous fluid.

[0044] Most of the light entering the eye 10 is refracted at the air—cornea interface. The cornea 16 has an index of refraction of 1.37, and is largely responsible for refracting light into the eye 10. The light then slightly diverges in the fluid-filled anterior chamber 18 which has an index of refraction close to that of water, e.g., approximately 1.33, and travels to the natural crystalline lens 24. The natural crystalline lens 24 is a biconvex structure having an index of refraction of 1.4 at its center and an index of refraction of 1.38 at its outer portion. Next to the cornea 16, the natural crystalline lens 24 is responsible for refracting much of the light entering the human eye 10. The anterior portion of the natural crystalline lens 24 converges light onto its posterior portion where light is then diverged. It is at this point, that the image being viewed is inverted. The inverted image (or light) then travels into the vitreous humor 30 and through the vitreous fluid. The vitreous fluid has an index of refraction close to that of water, e.g. 1.33. After the inverted image travels through the vitreous humor 30, it is brought to focus upon the retina. The retina is responsible for relaying electric signals to the optic nerve. The optic nerve then carries the message to the brain which translates the inverted image into its upright position.

[0045] Ocular adjustments for sharp focusing of objects viewed at different distances are accomplished by the action of the ciliary body 26 on the capsule 22 and natural crystalline lens 24 through the zonules 28. The ciliary body 26 contracts, allowing the capsule 22 to return to a more spherical shape for viewing objects near to the viewer. When the ciliary body 26 retracts, the ciliary body 26 pulls on the zonules 28 to make the capsule 22 more discoid thus permitting objects at a distance to be viewed in proper focus. (FIG. 1) To summarize, when the eye 10 focuses, the capsule 22 changes shape to appropriately distribute the light admitted through the cornea 16 and the iris 20.

[0046] Referring now to FIGS. 1-22, an IOL in accordance with the invention comprises an optic 32 operably coupled to an optic positioning member and implanted within the capsule 22 of the human eye 10. The IOL changes shape in response to ciliary body 26 movement. As previously noted, the optic 32 of the present invention is formed of a highly refractive material. The refractive material has an index of refraction of from about 1.36 to 1.5 or higher. Examples of preferred refractive materials include silicone oil, hydrocarbon oil, and more preferably silicone gel (available from Nusil Technology). When the refractive material used is a gel, the gel may be pre-formed into the desired optic shape and adhered onto the optic positioning member without encapsulating it.

[0047] The optic 32 may be utilized in a number of ways in a variety of optic positioning members. The optic positioning members discussed herein are preferably formed of any appropriate biologically inert material conventionally used in IOL construction (e.g., elastic, synthetic resin materials). Examples of suitable materials include acrylates (such as polymethylmethacrylates), silicones, and mixtures of acrylates and silicones. It is contemplated that mixtures of silicones and acrylates comprise both chemical mixtures, such as silicone-acrylate blends, and various combinations of silicones and acrylates employed to construct the lens. It is particularly preferred that the optic positioning members according to the invention be constructed of a material having an elastic memory (i.e., the material should be capable of substantially recovering its original size and shape after a deforming force has been removed). An example of a preferred material having elastic memory is MEMORYLENS (available from Mentor Ophthalmics in California).

[0048] The preferred embodiments of the IOL of the instant invention discussed immediately below demonstrate the variety of optic positioning members that may be operably coupled with the inventive optic to correct refractive errors in the eye. The terms rigid optic and resilient optic are used herein as relative terms to one another. For instance, a rigid optic may be any optic that is less resilient than the resilient optic of the present invention, even though the rigid optic may be more resilient than another rigid optic. The optics of the present invention may be made of varying degrees of resiliency and rigidity depending upon the materials used, therefore, the terms rigid and resilient should not be used as limiting terms other than to convey a specific relationship between two optics within the scope of this invention.

The IOL of FIGS. 1-3 [IOL 61]

[0049] The optic 32 presents a convex anterior surface 36 and a planar posterior surface 38 (hereinafter plano-convex). Although the optic 32 is illustrated as piano-convex, the size and shape of the optic 32 may be varied depending upon the user's eyesight. The optic 32 is composed of a refractive material 40 that is enveloped within a pre-formed capsule 42 formed of a thin continuous wall 43 made of the same flexible synthetic resin material as the optic positioning member 34. The thin wall 43 has an anterior section 33 facing the anterior portion 12 of the eye 10 and a posterior section 41 facing the posterior portion 14 of the eye 10 respectively. (See FIG. 2) The anterior section 33 of the thin wall 43 has a thickness of from about 0.0005 to 0.025 mm, and more preferably of about 0.004 mm, when the material used is silicone. The posterior section 41 of the thin wall 43 has a thickness of from about 0.0005 to 0.025 mm, and more preferably of about 0.003 mm, when the material used is silicone. One of ordinary skill in the art will appreciate that the anterior section 33 and the posterior section 41 of the thin wall 43 may also be constructed of uniform thickness. The optic 32 may also be constructed without the refractive material housed within the pre-formed capsule 42 when the refractive material used is the silicone gel material discussed above. (See FIG. 16)

[0050] The optic positioning member 34 may be integral with optic 32 or may be structurally distinct. As illustrated, the optic positioning member 34 comprises a main body 35 which includes an annular posterior segment 44 with a central opening 46 and an anterior segment 37. Anterior segment 37 and posterior segment 44 are located on either side of equatorial axis 56. A plurality of circumferentially spaced, arcuate in cross-section positioning legs 48 extend from the segment 44 and are joined to the margin of optic 32, with openings 50 defined between adjacent pairs of the legs 48. As perhaps best seen in FIG. 2, the legs 48 cooperatively present, with the optic 32, a substantially discoid shape with a central chamber 52. However, the legs 48 also define an annular equatorial segment 54 disposed on opposite sides of equatorial axis 56. (See FIG. 2) The overall IOL 61 further presents a central polar axis 58 as shown. Preferably, the outside dimension of the IOL 61 at the equatorial segment 48 is from about 8 to 12 mm. On the other hand, the outside dimension along polar axis 58 is typically from about 1 to 5 mm. These dimensions given immediately above, however, are only representative of some typical dimensions within the ambit of the present invention. A wide range of variance necessarily exists for the dimensions of the IOLs of this invention because a wide degree of biological variance exists. Clearly, the dimensions of the IOLs of the present invention must conform to the size and shape of the eye to be fitted. One of ordinary skill in the art will readily appreciate this.

[0051] The optic positioning member 34 discussed herein is configured so as to substantially conform with the capsule 22, particularly to the equatorial portion 27 of the capsule 22. This is shown in FIGS. 1 and 2 where it will be observed that the equatorial segment 54 of the IOL 61 is in substantially conforming contact with the inner surface of the equatorial portion 27 of capsule 22. This close conforming relationship is maintained notwithstanding the extent of accommodation of IOL 61.

[0052] IOL 61 is inserted into the human eye 10 in the following manner. An ophthalmic surgeon would remove the natural crystalline lens 24 by conventional methods, leaving an opening 21 in the anterior wall 23 of the capsule 22. IOL 61 is then folded into a compact size for insertion in the capsule 22 through opening 21. Once inserted, the capsule 22 is filled with fluids (e.g., saline solution) which enter the IOL 61 causing IOL 61 to return to its original, non-deformed state as shown in FIG. 1. There is no need to suture the IOL 61 to the capsule 22 because, due to the size and shape of IOL 61 and conformance of the IOL 61 to the capsule 22, the IOL 61 will not rotate or shift within the capsule 22.

[0053] Optionally, IOL 61 may be provided with a very thin membrane (not shown) in covering relationship as disclosed in U.S. patent application Ser. No. 09/940,018, filed Aug. 27, 2001, which is incorporated by reference herein. It is contemplated that the membrane would be formed of the same synthetic resin as the optic positioning member 34 but would be much thinner (on the order of a few thousandths of an inch) than the remainder of the optic positioning member 34. The purpose of the membrane is to prevent or at least impede the passage of migratory cells through openings within the IOL 61 and into the inner chamber of the IOL 61.

[0054] Furthermore, optic positioning member 34 construction is disclosed in previously filed application for U.S. patent Ser. No. ______ entitled Accommodating Intraocular Lens Implant and U.S. patent Ser. No. 09/940,018 entitled Intraocular Lens Implant Having Eye Accommodating Capabilities both to the same applicant, which are hereby incorporated by reference herein as is necessary for a full and complete understanding of the present invention.

[0055] Implantation of the inventive IOL 61 restores normal vision by providing an optic 32 formed of highly refractive material capable of bending light onto the retina. After implantation of the IOL 61 in the human eye 10, light refracts at the air-cornea interface in the same manner as the natural human eye 10. The light travels through the aqueous humor 18 and onto the optic 32. The radius of curvature of the optic 32 changes in response to ciliary body 26 movement, thus affecting the optic's 32 refractive capabilities.

[0056] Not only does the IOL 61 project an observed image onto the retina, but it also accommodates in response to action of the ciliary body 26 in connection with the zonules 28 to view objects located both near and far from the viewer. When the viewer is observing an image located at a distance, the sensory cells within the retina signal the ciliary body 26 to relax, thus pulling on the zonules 28 to make the capsule 22 more discoid as shown in FIG. 1. In doing so, the polar dimension of the capsule 22 narrows, subsequently causing the polar dimension of the IOL 61 to similarly narrow. Those ordinarily skilled in the art will appreciate that the optic positioning member 34 is operably coupled with the optic 32 of the present invention to change shape in response to ciliary body 26 movement. In this regard, the movement of the ciliary body 26 causes the optic 32 to move posteriorly and anteriorly, respectively. Contraction of the ciliary body 26 and subsequent relaxation of the zonules 28 will cause the optic 32 to vault anteriorly.

[0057] The IOL 61 of the present invention typically has a diopter value of from about 16 to 26. The diopter value of a lens is defined as the reciprocal of the focal length in meters:

Diopter=1/focal length (m).

[0058] Focal length is the distance from the center of the lens to the object being viewed. The focal length must decrease as magnification increases. The diopter value expresses the refractive capacity of a lens which is associated with the radius of curvature of the optics. Generally, an increased diopter value indicates that the optic is thicker and also has a lesser radius of curvature thus possessing greater light-bending capability.

The IOL of FIG. 4 [IOL 60]

[0059] The IOL 60 is similar to IOL 61 illustrated in FIGS. 1-3. IOL 60 comprises an optic positioning member 62 wherein the optic positioning member 62 presents an anterior segment 66 and a posterior segment 68 each having a central opening therein 67, 69. A plurality of individually continuous, circumferentially spaced, arcuate in cross-section positioning legs 64 extend from anterior segment 66 and are joined to the margin of optic 32, with openings 71 defined between adjacent pairs of the legs 64, by haptic arms 72. The haptic arms 72 extend between the posterior segment 68 to the margin of the optic 32. The haptic arms 72 join the optic 32 and the optic positioning member 62. This embodiment is similar to IOL 61 in that it may also be constructed with a thin membrane as disclosed in U.S. patent application Ser. No. 09/940,018, filed Aug. 27, 2001 which has been incorporated by reference herein.

[0060] In this embodiment, it is important that the posterior segment 68 of the optic positioning member 62 not be fixed with respect to the posterior portion of the capsule 22. This would not be the case if the posterior segment 68 was continuously connected with the positioning legs 64. While not shown in the figures, the anterior segment 66 may be continuously connected by an annular haptic. IOL 60 is implanted and operates in the same manner as IOL 61. The IOL 60 of the present invention typically has a diopter value of from about 16 to 26.

[0061] Furthermore, optic positioning member 62 construction is disclosed in previously filed application for U.S. patent Ser. No. ______ entitled Accommodating Intraocular Lens Implant and U.S. patent Ser. No. 09/940,018 entitled Intraocular Lens Implant Having Eye Accommodating Capabilities both to the same applicant, which are hereby incorporated by reference herein as is necessary for a full and complete understanding of the present invention.

The IOL of FIG. 5 [IOL 60 a]

[0062] A preferred IOL 60 a according to the invention is illustrated in FIG. 5. Similar to the IOL 60 embodiment described above, this IOL 60 a comprises an optic 32 and an optic positioning member 74 presenting an anterior segment 66 a and a posterior segment 68 a. A plurality of circumferentially spaced, arcuate in cross-section positioning legs 76 extend from the anterior segment 66 a to the optic 32. The haptic arm 72 a extends posteriorly from the anterior segment 66 a to the optic 32. In a further preferred embodiment of IOL 60 a, the optic 32 may be connected to the optic positioning member 74 via a plurality of haptic arms (not shown). The plurality of haptic arms are disposed at various locations about anterior segment 66 a and extend posteriorly towards the optic 32. The plurality of legs 76 are continuously attached to each other through continuous sections 80 presenting annular orifices 82 therethrough. This embodiment is similar to IOL 61 and 60 in that it may also be constructed with a thin membrane as disclosed in U.S. patent application Ser. No. 09/940,018, filed Aug. 27, 2001 which has been incorporated by reference herein.

[0063] IOL 60 a is implanted and operates in a similar manner to IOLs 61 and 60. The IOL 60 a of the present invention typically has a diopter value of from about 16 to 26. Furthermore, the construction of optic positioning member 74 is disclosed in previously filed application for U.S. patent Ser. No. ______ entitled Accommodating Intraocular Lens Implant and U.S. patent Ser. No. 09/940,018 entitled Intraocular Lens Implant Having Eye Accommodating Capabilities both to the same applicant, which are hereby incorporated by reference herein as is necessary for a full and complete understanding of the present invention.

The IOL of FIG. 6 [IOL 60 b]

[0064]FIG. 6 depicts yet another preferred IOL 60 b according to the invention. This IOL 60 b also comprises an optic 32 and an optic positioning member 84 presenting an anterior segment 66 b and a posterior segment 68 b. The optic positioning member 84 further comprises a plurality of circumferentially spaced, arcuate in cross-section positioning legs 88 having openings 86 therein between adjacent pairs of legs 88. In essence, the IOL 60 b is configured in much the same fashion as the IOL 60, with the exception that a plurality of haptic arms 72 b extend from equatorial segment 54 toward the optic 32. When the IOL 60 b is in its original, non-compressed state, the haptic arms 72 b are vaulted slightly toward anterior segment 66 b.

[0065] This embodiment is similar to IOL 61, 60, and 60 a in that it may also be constructed with a thin membrane as disclosed in U.S. patent application Ser. No. 09/940,018, filed Aug. 27, 2001 which has been incorporated by reference herein.

[0066] IOL 60 b is implanted and operates in a similar manner to IOLs 61, 60 and 60 a. The IOL 60 b of the present invention typically has a diopter value of from about 16 to 26. Furthermore, the construction of optic positioning member 84 is disclosed in previously filed application for U.S. patent Ser. No. ______ entitled Accommodating Intraocular Lens Implant and U.S. patent Ser. No. 09/940,018 entitled Intraocular Lens Implant Having Eye Accommodating Capabilities both to the same applicant, which are hereby incorporated by reference herein as is necessary for a full and complete understanding of the present invention.

The IOL of FIGS. 7 and 8 [IOL 61 d]

[0067] IOL 61 d is another embodiment of the present invention. IOL 61 d presents a variation upon the structure of IOL 61 wherein the optic 32 is bound to either the anterior surface 33 or the posterior surface 35 of the optic positioning member 34. IOL 61 d operates in and is implanted in the same manner as IOL 61.

[0068] Notably, IOL 61 d illustrated in FIGS. 7 and 8 comprises a liquid refractive material 40 enveloped within the capsule 42. The indices of refraction of the wall 43 and the refractive material 40 may be varied to satiate surgical, medical, or manufacturing needs.

The IOL of FIGS. 9 and 10 [IOL 61 a]

[0069] IOL 61 a differs from the embodiments discussed thus far in that while the optic 32 is operably coupled to the anterior segment 37 of the optic positioning member 34, a second rigid optic 90 is operably coupled to the posterior segment 44. The optics 32, 90 are positioned on opposed segments 37, 44 of the optic positioning member such that the optics 32, 90 share the same optical axis. Opposition or opposed in this context is used consistently in this application to mean positioned on the opposite side of equatorial axis 54 such that both optics share substantially the same optical axis, and are aligned such that the IOL provides undistorted vision. The posterior optic 90 is made of the same material as the optic positioning member 34, however, one of ordinary skill in the art will recognize that the posterior optic 90 may be constructed of the inventive refractive material as well.

[0070] This embodiment is implanted and operates in essentially the same manner as the IOLs discussed thus far, but differs because it includes a second opposed rigid optic 90. The anterior optic 32 converges light upon the posterior optic 90. The posterior optic 90, in turn, diverges the light onto the retina. Any irregularities in the cornea 16 or the natural crystalline lens 24 are counteracted by the highly refractive material 102, thereby bringing the image to focus upon the retina. This embodiment also accommodates in response to ciliary body 26 movement. When the ciliary body 26 contracts, the IOL 61 a assumes a spheroid shape. The anterior optic 32 moves anteriorly whereas the posterior optic 90 moves posteriorly. When the ciliary body 26 retracts, the zonules 28 exert a tensional pull upon the IOL to change the IOL to a discoid shape. The anterior optic 32 moves posteriorly whereas the posterior optic 90 moves anteriorly. The IOL 61 a of the present invention typically has a diopter value of from about 16 to 26.

[0071] IOL 61 a may also be positioned within the eye 10 such that the rigid optic 90 is located anteriorly and the optic 32 is positioned posteriorly as illustrated in FIG. 10. When the IOL 61 a is positioned within the eye 10 in this manner, the IOL 61 has a combined total refraction of about 16 to 26 diopters.

The IOL of FIGS. 11-15 [IOL 92]

[0072] Another preferred embodiment of the present invention includes an anterior optic 94 a and a posterior optic surface 96 a integral with an optic positioning member 98, such that the IOL 92 presents a unitary structure for implantation within the capsule 22 of the human eye 10. (See FIG. 11) IOL 92 comprises a main body presenting a pre-formed enclosed flexible bag 100 having resilient fill material 102 therein. The pre-formed enclosed flexible bag 100 may also be filled with other refractive media disclosed herein. Flexible bag 100 comprises an anterior segment 104, and a posterior segment 106. Flexible bag further includes wall 112 which, when viewed in cross-section, forms and extends radially from an anterior arcuate wall segment 94 and converges upon the posterior segment 106 of the IOL 92 to form an opposing posterior arcuate wall segment 96. The opposing arcuate wall segments 94, 96 define opposed anterior and posterior optic surfaces 94 a, 96 a when cavity 114 of enclosed flexible bag 100 is filled with material 102. Although the terminology ‘optic surface’ is used herein to describe surfaces 94 a and 96 a, these surfaces 94 a, 96 a, operate functionally as optics. Therefore, the term optic may be used interchangeably to describe optic surfaces 94 a, 96 a within the remainder of this disclosure.

[0073] The anterior optic surface 94 a and the posterior optic surface 96 a have a combined radius of curvature of from about 16 to 26 diopters. (See FIG. 11) The anterior optic surface 94 a and the posterior optic surface 96 a are both illustrated as convex in shape. When viewed in cross-section, anterior segment 94 and posterior segment 96 are connected by a pair of opposed arcuate equatorial segments 124 a as shown in FIG. 14.

[0074] Wall 112 includes a fill aperture 118 with a plug therein closing the aperture 118. Although aperture 118 is illustrated at location 120 of the IOL 92, the aperture 118 can be formed at any location on the IOL 92. Preferably the IOL 92 will have an outer equatorial diameter (distance of IOL 92 taken through equatorial axis 124) of from about 8 to 12 mm. (See FIG. 13) Preferably the IOL will have an outside dimension through the central polar axis 122 of from about 2 to 5 mm. (See FIG. 13)

[0075] An ophthalmologist fills cavity 114 with material 102 prior to surgical implantation of the IOL 92 within the human eye 10 by inserting the material 102 through the aperture 118. After cavity 114 is filled, the aperture 118 is sealed. The ophthalmologist removes the natural crystalline lens 24 by conventional methods, leaving an opening in the anterior wall 54 of the capsule 22. The IOL 92 is folded and inserted within the capsule 22 through the opening. Implantation of the IOL 92 does not require suturing of the eye 10 because the instant IOL 92 is capable of being implanted through a small opening in the capsule 22.

[0076] IOL 92 operates in the same manner as IOL 61 a because IOL 92 includes opposed optic surfaces 94, 96. Anterior optic 94 converges light upon the posterior optic 96, which in turn, diverges light onto the retina. The IOL 92 responds to contraction of the ciliary body 26 by assuming a spheroid shape.

IOL of FIG. 16 [IOL 61]

[0077]FIG. 16 illustrates optic 32 of the inventive IOL 61 formed from a resilient silicone gel material. Therefore, the IOL 61 of FIG. 16 does not depict the refractive material enveloped within a pre-formed capsule 42 having a thin continuous wall 43. The capsule 42 is not needed when the refractive material is formed from a resilient, shape-retaining synthetic material such as the silicone gel discussed above.

IOL of FIG. 17 [IOL 61 c]

[0078] Another preferred embodiment of the present invention includes an optic positioning member 34 operably coupled with two optics 142, 144 to change shape in response to ciliary body 26 movement. IOL 61 c includes a resilient optic 142 surrounded by a rigid optic 144. The resilient optic 142 is formed of the refractive material discussed above. The rigid optic 144 is formed of the same material as the optic positioning member 34. Both optics 142, 144 are housed within a pre-formed capsule 42 as described in connection with IOL 61.

[0079] IOL 61 c operates in a similar manner as the embodiments discussed so far, but differs in that the resilient optic 142 surrounded by the rigid optic 144 maintains a constant volume in response to ciliary body 26 movement. The constant volume of the resilient optic 142 coupled with the relatively high refractive index of the refractive material contained therein confers increased light-bending properties upon the resilient optic 142.

IOL of FIGS. 18 and 19 [IOL 200]

[0080] Another preferred embodiment is an IOL 200 having an annular optic positioning member 210 presenting spaced-apart arcuate anterior 212 and posterior segments 214. The IOL 200 further includes an anterior resilient optic 216 and a posterior rigid optic 218 operably coupled to the optic positioning member 210 to change shape in response to ciliary body 26 movement.

[0081] The anterior segment 212 of the optic positioning member 210 contains an opening 220 of from about 7 to 3 mm, and more preferably of about 4 mm wide. The anterior segment 212 further includes an outer margin 222 and an inner margin 224. The outer margin 222 is defined as the anterior portion of the anterior segment 212, or that portion of the segment 212 closest to the iris 20. The posterior segment 214 also includes an inner margin 226 and an outer margin 228 wherein the inner margin 226 of the posterior segment 214 is the margin closest to the iris 20 as well. The space between the anterior segment 212 and the posterior segment 214 is occupied by refractive material such that the refractive material is adjacent to the inner margins 224, 226 of the segments 212, 214. The refractive material protrudes beyond the outer margin 222 of the anterior segment 212. This protrusion defines the resilient optic 216. The refractive material used herein is the refractive silicone gel discussed above. The silicone gel refractive material may be pre-formed into the desired shape and connected, by posts, to the segments 212, 214 of the optic positioning member 210. The refractive material may also be encompassed within a bladder which is also similarly connected to the segments 212, 214. In this case, the refractive material used may also be a liquid.

[0082] The IOL 200 may further include a second rigid optic 218 opposed to resilient optic 216. The rigid optic 218 is made of the same material as the optic positioning member 210 and is supported by the posterior segment 214. As mentioned above, the space between the segments 212, 214 is occupied by refractive material. This IOL 200 differs from the other embodiments discussed herein because the refractive material is not completely contained by the optic positioning member 210 in addition to the optic 216 defining protrusion which extends beyond the outer margin 222 of the anterior segment 212. The refractive material is positioned between the two segments 212, 214 such that the refractive material comes into direct contact with the biological capsule 22 at locations 230.

[0083] IOL 200 is implanted in the same manner as IOL 61 after IOL 200 is assembled, and operates in a similar manner to the other IOLs having opposed optics discussed herein. Contraction of the ciliary body 26 and subsequent relaxation of the zonules 28 exerts force upon the refractive material causing the material to protrude outward to extend beyond the outer margin 222 of the anterior segment 212. When the ciliary body 26 retracts, the zonules 28 exert a tensional pull upon the capsule 22, and the refractive material assumes its more flattened shape to view objects located at a distance.

IOL of FIGS. 20 and 21 [IOL 61]b]

[0084] The IOL 61 b illustrated in FIGS. 20 and 21 demonstrate yet another preferred embodiment of the invention. FIGS. 20 and 21 demonstrate any of the IOLs of FIGS. 1-8 and 16 discussed above positioned within the eye 10 such that the optic 32 is positioned posteriorly. One of skill in the art would readily appreciate that although FIGS. 20 and 21 illustrate any of the IOLs of FIGS. 1-8 and 16 in the vertical sectional view, any of the IOLs of the present invention may be positioned such that the anterior optic faces posteriorly. FIG. 20 illustrates the IOL of the present invention in the accommodated shape. FIG. 21 illustrates the IOL in the disaccommodated shape.

IOL of FIG. 22 [IOL 61 e]

[0085] IOL 61 e illustrated in FIG. 22 is similar to IOL 61 c illustrated in FIG. 17. IOL 61 e differs from IOL 61 c in that the resilient optic 142 a surrounds the rigid optic 144 a. FIG. 22 illustrates IOL 61 e positioned posteriorly in the capsule 22 of the eye 10. The resilient optic 142 a changes shape in response to ciliary body 26 movement. The change in curvature of the resilient optic 142 a provides about 3 diopters of convergence while the rigid optic 144 a essentially maintains its shape.

[0086] Although the invention has been described with reference to the preferred embodiment illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. For example, the IOLs of the present invention may all be constructed in the disaccommodated or accommodated shapes. Also, while the foregoing method of inserting the IOL into the capsule 22 presumed that a portion of the anterior wall 54 of the capsule 22 would be removed with the natural crystalline lens 24, it will be appreciated that it may be possible to insert the IOL through an incision in the posterior wall 53 of the capsule 22. Furthermore, while the foregoing description discloses that the IOL could be utilized to correct refractive error, the IOL may be used in any situation where the natural crystalline lens 24 should be replaced. For example, the IOL may be used to correct myopia, hyperopia, presbyopia, cataracts, or a combination thereof. Various refractive media may be used to fill cavity 114 of IOL depending upon the desired index of refraction. 

I claim:
 1. In an implantable intraocular lens including a light-transmitting optic and adapted for positioning within the capsule of a human eye as a replacement for the natural lens, the improvement which comprises an optic formed from resilient, shape-retaining synthetic material.
 2. The lens of claim 1, said material being substantially transparent.
 3. The lens of claim 2, said material having an index of refraction of at least about 1.36.
 4. The lens of claim 1, said material being formed of a biologically inert material.
 5. The lens of claim 4, said material comprising silicone.
 6. The lens of claim 1, said material being a gel.
 7. The lens of claim 1, said material having an elastic memory.
 8. The lens of claim 1, said lens further comprising a positioning member operably coupled with said optic and responsive to ciliary body movement in order to change the shape of said optic.
 9. The lens of claim 8, said positioning member comprising a main body including anterior and posterior segments, said optic being connected to either segment of said positioning member.
 10. The lens of claim 9, said lens further including a rigid optic surrounding said resilient optic, said rigid optic formed of synthetic resin material selected from the group consisting of the silicones, acrylates, and mixtures thereof.
 11. The lens of claim 8, said positioning member comprising spaced-apart anterior and posterior segments, said optic being connected to either segment of said positioning member.
 12. The lens of claim 11, said lens further including a rigid optic opposed to said resilient optic, said rigid optic formed of synthetic resin material selected from the group consisting of the silicones, acrylates, and mixtures thereof.
 13. The lens of claim 12, said optics being substantially between and captively retained by said segments.
 14. The lens of claim 13, said lens including an optic defining protrusion extending beyond adjacent outer edges of the margins of said anterior segment.
 15. The lens of claim 14, said rigid optic being supported by said posterior segment.
 16. The lens of claim 8, said positioning member being formed of a synthetic resin material.
 17. The lens of claim 16, said synthetic resin material comprising a biologically inert material.
 18. The lens of claim 16, said synthetic resin material comprising a material selected from the group consisting of the silicones, acrylates, and mixtures thereof.
 19. The lens of claim 1, said lens presenting opposing anterior and posterior optic surfaces.
 20. The lens of claim 19, said lens further including a positioning member operably coupled with said anterior and posterior segments, said positioning member comprising a pair of opposed arcuate sections, in cross-section, between the anterior and posterior optic surfaces.
 21. The lens of claim 20, said optic comprising an enclosed flexible bag with resilient fill material therein.
 22. The lens of claim 21, said material being substantially transparent.
 23. The lens of claim 22, said material having an index of refraction of at least about 1.36.
 24. The lens of claim 21, said material being formed of a biologically inert material.
 25. The lens of claim 21, said material being formed of a compound comprising silicone.
 26. The lens of claim 21, said material being a gel.
 28. The lens of claim 21, said material having an elastic memory.
 29. The lens of claim 21, said bag further comprising a fill aperture with a plug therein closing the aperture.
 30. The lens of claim 1, said lens having an equatorial diameter of from about 8 to 12 mm.
 31. The lens of claim 1, said lens having a polar height of from about 2 to 5 mm.
 32. The lens of claim 1, said lens having a diopter value of from about 16 to
 26. 33. An implantable intraocular lens comprising: a resilient light-transmitting optic formed of a synthetic light-refractive material; and a flexible positioning member coupled with the optic and operable, when the lens is placed within a human eye capsule, for changing the shape of said lens in response to ciliary body movement.
 34. The lens of claim 33, said material being substantially transparent.
 35. The lens of claim 34, said material having an index of refraction of at least about 1.36.
 36. The lens of claim 33, said material being formed of a biologically inert material.
 37. The lens of claim 33, said material being formed of a compound comprised of silicone.
 38. The lens of claim 37, said material being formed of a liquid.
 39. The lens of claim 33, said material being formed of a compound comprising hydrocarbons.
 40. The lens of claim 39, said material being formed of a liquid.
 41. The lens of claim 37, said material being formed of a gel.
 42. The lens of claim 41, said lens further comprising a fixed optic formed of synthetic resin material.
 43. The lens of claim 39, said liquid enveloped within a capsule having an anterior section and a posterior section.
 44. The lens of claim 43, each of said sections individually having a wall thickness of from about 0.0005 to 0.025 mm. 